Presentation of differences between multiple searches

ABSTRACT

The present invention is directed towards systems and methods for generating and displaying the difference between a primary result set and a secondary result set. According to the present invention, a method for displaying the difference between a primary result set and a secondary result set for a query comprises generating a primary result set and a secondary result set, the primary result set and secondary result set generated according to one or more respective disparate search algorithms. A difference result set is determined according to a difference between items in the primary result set and second result set, which is displayed to a user.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosures, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

BACKGROUND OF THE INVENTION

The invention disclosed herein relates generally to a system and methodfor comparing result sets that are responsive to searches over a corpusof documents. More particularly, the present invention relates tosystems and methods for generating and presenting a difference resultset comprising items selected according to a difference between aprimary result set and a secondary result set.

When using search engines made available by commercial search providers,users are not always satisfied with the search results that these searchengines generate. In an attempt to overcome perceived shortcomings withavailable search engines, meta-search engines provide aggregate resultsfrom a plurality of search engines to generate a meta-result set bydetermining the union of the result sets from a plurality of searchengines. These meta-search engines, however, apply proprietary rankingalgorithms to the meta-result set, which may result in items that arepotentially relevant to a given user receiving a low ranking andtherefore not being utilized.

What is therefore needed are systems and methods that allow a user toview a difference result set comprising differences between a result setgenerated by a first search engine using a first search and rankalgorithm, and a secondary result set generated by a second searchengine using a second search and rank algorithm. Systems and methods arealso needed to track selections in the difference result set, which maybe used in improving the searching and ranking of items by the firstsearch engine.

SUMMARY OF THE INVENTION

The present invention is directed towards systems and methods for thegeneration and presentation of a difference between a primary result setand a secondary result set. According to one embodiment, the inventionis directed towards a method for influencing a search algorithm in thegeneration of a result set. According to the present embodiment, themethod comprises receiving a primary result set and a secondary resultset in response to a search query, the primary result set and secondaryresult set each comprising one or more items, and determining adifference between the one or more items in the primary result set andthe one or more items in the secondary result set for storage as adifference result set. An item in the difference result set is selected,and an indication of the selected item is stored for use in influencingitems contained in a result set. According to one embodiment, a searchengine that generated the primary result set generates the result set.

Receiving the primary result set may comprise a first search enginegenerating the first result set and receiving a secondary result set maycomprise a second search engine generating the secondary result set.Furthermore, generating the primary result set and the secondary resultset may comprise generating the primary result set according to a firstsearch algorithm and generating the secondary result set according to asecond search algorithm. A user profile may be provided in which a useridentifies a preferred search engine from which to generate thesecondary result set. Alternatively, a default preferred search enginemay be used.

Determining the difference result set may be accomplished according to avariety of techniques. According to one embodiment, determining thedifference result set comprises determining the difference according toURL matching. Alternatively, determining the difference result set maycomprise crawling one or more pages identified by one or more items inthe primary result set and the secondary result set to determine one ormore page signatures and comparing the one or more page signatures todetermine a duplicate page. Duplicate pages are eliminated from thedifference result set. Feedback may also be elicited from a userregarding the selection of an item in the difference result set.

The method of the present invention is further applicable to searchesfor all forms and types of media content. For example, the primary andsecondary result sets may comprise result sets generated in response tosearches for items of audio content. Similarly, the primary andsecondary result sets may comprise result sets generated in response tosearches for items of video content, image content, text content, aswell as combinations thereof.

The present invention is also directed towards a method for thepresentation of a difference between a primary result set and asecondary result set. According to one embodiment, a method fordisplaying the difference between one or more result sets for a querycomprises generating a primary result set and a secondary result set,each of the primary and secondary result sets generated according to oneor more respective disparate search algorithms. A difference result setis determined according to a difference between items in the primaryresult set and secondary result set. The difference result set isdisplayed to a user, which may comprise displaying a difference controlto the user, selection of the difference control causing the display ofthe difference result set.

The difference control may be selectively displayed to the user.According to one embodiment, determination of whether the differencecontrol is to be displayed to a given user comprises determining if theuser is a registered user and, if the user is a registered user,displaying the difference control. Alternatively, the determination ofwhether the difference control is to be displayed to a given usercomprises retrieving a past observed behavior of the user and displayingthe difference control on the basis of the past observed behaviorsatisfying one or more criteria. Retrieving the past observed behaviormay comprise retrieving the past observed behavior from a user profilefor the user.

The present invention is also directed towards a method for presenting aresult set with an indication of an item that is exclusive to the resultset. The method comprises receiving a primary result set and a secondaryresult set in response to a search query, the primary result set andsecondary result set each comprising one or more items. A determinationis made to determine an exclusive item contained in the primary resultset that is not contained in the secondary result set. The primaryresult set is displayed to the user and an indication is displayed withthe exclusive item, indicating that the exclusive item is contained inthe primary result set and not contained in the secondary result set,e.g., the item is exclusive to the primary result set. The indicationmay comprise displaying an icon, which may be an animated icon, and mayalternatively or in conjunction comprise displaying text or otherindications. In addition to the foregoing, or in conjunction, the methodmay comprise indicating common items between the primary and secondaryresult sets.

Determining according to one embodiment comprises determining adifference between the one or more items in the primary result set andthe one or more items in the secondary result set. The primary resultset may be generated according to a first search algorithm and thesecondary result set generated according to a second search algorithm.According to one embodiment, the method comprises eliciting feedbackfrom a user regarding the selection of the exclusive item, which maycomprise recording the selection of the exclusive item and/or modifyingthe ranking of the exclusive item in the primary result set on the basisof the elicited feedback.

A check may be performed to determine if the user is a registered user.Where the user is not a registered user, the indication is not displayedto the user with the exclusive item. The past observed behavior of theuser may also be retrieved and the indication displayed to the user withthe exclusive item on the basis of the past observed behavior. The pastobserved behavior for the user may be retrieved from a profile for theuser.

The present invention is further directed to methods for determining aresult set on the basis of sequential searches to determine differencesbetween the sequential searches. According to one embodiment, the methodcomprises receiving a primary result set comprising one or more items inresponse to a first search query, the first search query comprising afirst set of one or more search terms. A secondary result set comprisingone or more items is received in response to a second search query, thesecond search query comprising a second set of one or more search termsthat are a derivative of the first set of one or more search terms. Adifference is determined between the one or more items in the primaryresult set and the one or more items in the secondary result set todetermine a difference result set, the difference result set comprisingone or more items. The one or more items in the difference result setare displayed to the user. According to one embodiment, receiving aprimary result set and a secondary result comprises receiving twosequential searches.

The present method may further comprise receiving a tertiary result setcomprising one or more items in response to a third search query, thethird search query comprising a third set of one or more terms that area derivative of the second set of one or more search terms. A differenceresult set is determined on the basis of the difference between the oneor more items in the tertiary result set and the one or more items inthe difference result set to determine a secondary difference resultset, the secondary result set comprising one or more items. The one ormore items in the secondary difference result set are displayed to theuser. According to one embodiment, receiving a primary result set, asecondary result and tertiary result set comprises receiving threesequential searches. The result sets may be generated according tosimilar or disparate search algorithms.

A difference button may be selectively displayed to a user, theselection of which initiates display of the difference result set. Acheck may be performed to determine if the user is a registered userand, if the user is a registered user, display the difference button.The check may further comprise retrieving a past observed behavior ofthe user and displaying the difference button on the basis of the pastobserved behavior. According to one embodiment, retrieving the pastobserved behavior comprises retrieving the past observed behavior from aprofile for the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the figures of the accompanying drawingswhich are meant to be exemplary and not limiting, in which likereferences are intended to refer to like or corresponding parts, and inwhich:

FIG. 1 is a block diagram illustrating a system architecture for thegeneration and presentation of a difference result set generated on thebasis of a difference between a primary result set and a secondaryresult set according to one embodiment of the present invention;

FIG. 2 is a block diagram illustrating a data store for the storage ofone or more cached queries and associated result sets from one or moresearch engines according to one embodiment of the present invention;

FIG. 3 is a flow diagram illustrating a method for the generation andpresentation of, as well as interaction with, a difference result setgenerated on the basis of a difference between a primary result set anda secondary result set according to one embodiment of the presentinvention;

FIGS. 4 and 5 are flow diagrams illustrating a method for the generationand presentation of, as well as interaction with, a difference resultset generated on the basis of a secondary result set according to oneembodiment of the present invention;

FIG. 6 is a flow diagram illustrating a method for the generation andpresentation of a difference result set generated on the basis ofmultiple sequential queries according to one embodiment of the presentinvention;

FIG. 7 is a flow diagram illustrating a method for determining andindicating items in a difference result set in conjunction with items ina primary result set according to one embodiment of the presentinvention;

FIG. 8 is a screen diagram illustrating the presentation of a primaryresult set generated by a search engine in conjunction with a controlfor generating and presenting a difference result set according to oneembodiment of the present invention;

FIG. 9 is a screen diagram illustrating the presentation of a primaryresult set in conjunction with a difference result set according to oneembodiment of the present invention; and

FIG. 10 is a screen diagram illustrating the presentation of a resultset by a search engine with an indication of items in the result setthat are exclusive to the search engine according to one embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 through 7, embodiments of the presentinvention are shown. FIG. 1 presents a block diagram illustrating thecomponents of a system for generating and presenting a difference resultset on the basis of a difference between a primary result set and asecondary result set, which may comprise one or more secondary resultsets. Although the embodiment presented in FIG. 1 illustrates thesecomponents in a networked environment, it should be understood by thoseof skill in the art that the invention is not limited to networkedenvironments, and may also be implemented on a stand-alone computer orelectronic device. Furthermore, although FIG. 1 illustrates a number ofclient and server components, the invention is not limited to the use ofmultiple components, and all functionality regarding the same may beprovided by a lesser or greater number of components, depending, forexample, on scalability requirements.

As shown, the system of FIG. 1 includes a search provider 102, a network116, one or more content sources 118, one or more search engines 120 and122 that are remotely located from the search provider 102, and one ormore clients 124, 126 and 128. The search provider 102 allows clients124, 126 and 128 to search for and identify content items of interestthat are hosted by the one or more content sources 118. To allow clients124, 126 and 128 to search for content items from the one or morecontent sources, the search provider 102 makes use of a number ofcomponents, which may include a crawling component 104, an indexingcomponent 106, an index data store 108, and a search engine 110.

The search provider 102 is communicatively coupled to a network 116,which may include a connection to one or more local and/or wide areanetworks, such as the Internet. Using communication pathways that thenetwork 116 provides, the crawling component 104 is capable of accessingsources of content 118, as well as information regarding and describingthe same, which is referred to herein as metadata. The crawlingcomponent 104 communicates with content sources 118 for maintainingcached copies of the content and metadata in a content data store 100.The collection of content and metadata from content sources 118 isreferred to as “crawling”, and is the process by which the crawlingcomponent 104 collects information upon which the search engine 110performs searches. Exemplary methods for crawling information on anetwork are described in commonly owned U.S. Pat. No. 6,021,409,entitled “METHOD FOR PARSING, INDEXING AND SEARCHING WORLD-WIDE-WEBPAGES,” the disclosure of which is hereby incorporated by reference inits entirety.

The crawling component 104 crawls content located on content sources 118in communication with the network 116, such as the Internet, collectingcontent and information regarding the same. An indexing component 106parses and indexes content and related information that the crawlingcomponent 104 collects through the crawling process. The indexingcomponent 106 generates an index that defines a structure for thecontent and metadata that allows for location and retrieval of thecontent and metadata. According to one embodiment of the invention, theindex component 106 creates an index of word-location pairs that allowsa search engine 110 to determine specific items of content and metadataregarding the same in response to a query from a client 124, 126 and128, which may be from a user, software component, automated process,etc. Exemplary methods for indexing information is described in commonlyowned U.S. patent application Ser. No. 5,745,889, entitled “METHOD FORPARSING INFORMATION OF DATABASE RECORDS USING WORD-LOCATION PAIRS ANDMETAWORD-LOCATION PAIRS,” the disclosure of which is hereby incorporatedby reference in its entirety. Index information that the index component106 generates is written to an index data store 108 for persistentstorage and use by other components of the search provider 102.

The search engine 110 receives search requests from client devices 124,126 and 128 communicatively coupled to the network 116. A client device124, 126 and 128 may be any device that allows for the transmission ofsearch requests (a query or query fragment) to a search provider 102, aswell as receipt of result sets from the search provider 102. Accordingto one embodiment of the invention, a client device 124, 126 and 128 isa general purpose personal computer comprising a processor, transientand persistent storage devices, input/output subsystem and bus toprovide a communications path between components comprising the generalpurpose personal computer. For example, a 3.5 GHz Pentium 4 personalcomputer with 512 MB of RAM, 40 GB of hard drive storage space and anEthernet interface to a network. Other client devices are considered tofall within the scope of the present invention including, but notlimited to, hand held devices, set top terminals, mobile handsets, etc.The client device 124, 126 and 128 may run software applications, suchas a web browser, which provide for transmission of search requests aswell as receipt and display of result sets.

When the search engine 110 receives a search request, or query, from agiven client 124, 126 and 128, the search engine 110 investigates theindex in the index data store 108 to identify content that is responsiveto the query that the search engine 110 receives. The search engine 110generates a primary result set that comprises links to content fallingwithin the scope of the query. To present the client 124, 126 and 128with the most relevant items in the result set, the search engine 110may rank the items in the result set. Exemplary systems and methods forranking search results are described in commonly owned U.S. Pat. No.5,765,149, entitled “MODIFIED COLLECTION FREQUENCY RANKING METHOD,” thedisclosure of which is hereby incorporated by reference in its entirety.

According to the embodiment illustrated at FIG. 1, the search engine 110is operative to interface with a difference component 112 fordetermining a difference result set on the basis of a difference betweena primary result set and a secondary result set. According to oneembodiment of the invention, the search engine 110 at the searchprovider 102 receives a query directly from a user and generates theprimary result set, and one or more search engines 120 and 122 locatedremotely from the search provider 102 generate one or more secondaryresult sets. The difference component 112 receives the query from thesearch engine 110 and queries a result set data store 114 to identifyone or more secondary result sets. Alternatively, the differencecomponent 112 may operate in conjunction with one or more search engines120 and 122 that are located remotely from the search provider 102 togenerate one or more secondary result sets.

A search engine 120 and 122 that is located remotely from the searchengine 110 at the search provider 102 produces one or more secondaryresult sets. The search engine 120 and 122 that generates a secondaryresult set preferably generates the secondary result set according to asearch algorithm that is different from the search algorithm that thesearch provider 102 uses to generate the primary result set.Accordingly, the difference result set allows the user to determine anydifferences between the outputs of the two algorithms and may thereforeobjectively judge the superiority of the two algorithms. For example,where the search engine that generates the primary result set is theYahoo! Search engine and the MSN Search engine generates the secondaryresult set, the difference component 112 may generate a differenceresult set on the basis of differences between the two result sets.

The difference component 112 is operative to periodically query one ormore search engines 120 and 122, storing the queries and associatedsecondary result sets in a result set data store 114. Alternatively,secondary result sets, as well as difference result sets, may bemaintained at one or more client devices 124, 126 and 128. It shouldalso be noted that a given secondary result set may be rerun and updatedover time, e.g., every day. According to one embodiment, the differencecomponent 112 receives detailed information from the search engine 110regarding queries that users have been submitting to the search engineover a given period of time, e.g., the past day, the past week, etc. Onthe basis of this information, the difference component 112 instructsthe search engine to execute one or more queries.

The difference component 112 stores the result sets for the one or morequeries in the result set data store 114, which may comprise storing theresult sets on a per search engine basis, as is explained in greaterdetail herein. For example, the search engine 110 may determine the topone hundred most popular queries for the past week, which it provides asa list or other data file or structure to the difference component 112.The difference component 112 uses the list that it receives from thesearch engine 110 to query other search engines 120 and 122, storing thequeries and associated result sets in the result set data store 114 on aper search engine basis.

As an alternative, the difference component 112 may be comprised of ormake use of programming logic at clients 124, 126 and 128 in collectingand generating one or more secondary result sets, or other functionalityof the difference component described herein. According to oneembodiment, a client 124, 126 and 128 utilizes a toolbar that providesclient-side difference component logic, for example the Yahoo! Toolbar,which is a plug-in for multiple browser platforms that provides serveraccessible client-side logic, in addition to other functionality. Whenthe user submits a query to the search engine 110, the differencecomponent 112 instructs the client-side logic (or client-side logiclocated at the client device in the absence of instructions from thedifference component 112) to submit the query to other search engines120 and 122, which the client 124, 126 and 128 receives and forwards tothe service provider 102 for storage in the result set data store 114.Accordingly, the result set data store 114 maintains result sets for anumber of queries from different search engines 120 and 122. It shouldbe noted by those of skill in the art that the logic of the differencecomponent may be distributed, reside locally on a given client device124, 126 and 128, or combinations thereof, e.g., a client performing URLmatching with the difference component performing signature analysis asis described in greater detail herein.

The difference component 112 may request one or more secondary resultsets through the use of client-side scripting code that the searchengine 110 provides to clients 124, 126 and 128 as part of the userinterface for submitting search queries and receiving primary resultsets. When the user selects a given control that the search engine 110provides as part of the user interface, client-side code, e.g.,JavaScript, may query other search engines 120 and 122 using the querythat the user provided to the search provider 102 to generate one ormore secondary result sets. The client 124, 126 and 128 receives thesecondary result sets from the search engine 120 and 122, provides thedata for the difference component 112 and optionally caches a copy on aclient-side storage device, which may reside on the network 116 as anetwork attached storage (“NAS”) or similar network storage.

Regardless of the manner in which the difference component 112 receivesthe primary and secondary result sets, the difference component 112generates a difference result set indicating one or more differencesbetween the primary result set and the secondary result set. Thedifference component 112 may generate the difference result setaccording to a variety of techniques. According to one embodiment, thedifference component 112 performs URL matching on URLs contained in theprimary result set and the secondary result set, whereby duplicate URLsare excluded from the difference result set. Alternatively, thedifference component 112 may utilize “fingerprinting” techniques tocreate a signature or a fingerprint for a given page. Accordingly, wherethe fingerprint for a page in the primary result set is identical (orfalls within a threshold of similarity), the page is excluded from thedifference result set. Also, the difference component 112 may useknowledge of the structure of certain web sites and content sources 118to determine where two pages or URLs identifying pages are the same.Those of skill in the art should recognize that other techniques fordetermining the similarity of two items are well known and may beutilized by the difference component 112 in generating the differenceresult set.

The difference component 112 generates the difference result set on thebasis of the primary result set that the search engine 110 generates inresponse to the user's query, as well as one or more secondary resultsets generated by search engines 120 and 122 that are located remotelyfrom the search provider 102. According to one embodiment, uponselection of a user interface control by the user at the client 124, 126and 128, the difference component 112 generates the difference resultset, which the search engine 110 transmits to the client 124, 126 and128 for display to the user. The user may interact with both the primaryresult set that the search engine 110 at the search provider 102provides, as well as the difference result set that the differencecomponent 112 provides. A user's queries and other interactions aremaintained in a profile data store 115 as one or more user profiles.Alternatively, a client device 124, 126 and 128 may maintain a profilefor a given user using a given client device, e.g., as a cookie.

The profile data store 115 maintains one or more profiles, each profilecorresponding to a given user who may interface with the search provider102 through the use of a client device 124, 126, and 128. A profile 113for a given user maintains information regarding a given user, queriesthat the user submits to the search engine 110, a user's interactionwith primary and secondary result sets, etc. A user profile may alsomaintain a user's preferred search engines 120 and 122 from which toretrieve secondary result sets for use in generation of a differenceresult set. Alternatively, the user's profile may maintain an indicationof a default search engine 120 and 122, or the information in the user'sprofile may be analyzed to determine a predicted preferred searchengine. A user profile may further maintain a threshold value used ingenerating a difference result set. The threshold value may be used togenerate a difference result set comprised of results which appear abovethe threshold value in a primary result set and below the thresholdvalue in a secondary result set.

According to one embodiment, the user may choose to view the differenceresult set by selection of a difference button or similar control thatthe search engine 110 provides as part of a search user interface, e.g.,to view search queries and view result sets. The search engine 110 mayselectively display the difference button to users, such that not allusers are capable of displaying the difference result set. Thedetermination of the set of users to whom the search engine 110 providesthe difference button may be made on the basis of a number of factors.According to one embodiment, the difference button is shown to allusers. According to another embodiment, the search engine 110 mayanalyze a given user's characteristics or a user profile for a givenuser in the profile data store 115 to determine if the difference buttonshould be shown. The search provider 102 may also analyze server, ISPand other logs to determine whether search engine 110 should show thedifference button to the users, e.g., determining those users who haverecently switched to or from an alternate search provider.Alternatively, the search engine 110 may display the difference buttononly in response to certain queries the search engine 110 receives,e.g., queries to which the search engine 110 has received good feedbackfrom users regarding the primary result set that the search engine 110generates in response to the query. Geographical factors may also beemployed. The determination may also be made on the basis of an actual,stored or predicted primary, secondary or difference result sets,including the items contained therein and the query terms in response towhich a search engine or other component generates the result set. Thoseof skill in the art should recognize that a number of other accesscontrol factors may be taken into account or utilized in determiningwhether to present the difference button to a given user, and that thesetechniques fall within the scope of the present invention.

As indicated above, the difference component 112 may utilize a resultset data store 114 to maintain cached copies of secondary result setsfrom one or more search engines that are located remotely from thesearch provider. FIG. 2 presents a block diagram illustrating oneembodiment of the result set data store. According to the data store 202illustrated by FIG. 2, the data store 202 is delimited, partitioned orotherwise separated into a number of data structures on a per searchengine basis 204, 206 and 208, e.g., a separate data structure for theresult sets from each search engine.

A given one of the one or more per search engine data structures 204,206 and 208 maintains past queries 210, 212 and 216 that users submit tothe search provider's search engine. Each past query 210, 212 and 216maintains the search terms comprising the search query 218, 220 and 222,as well as the secondary result set 224, 226 and 228 that a given searchengine generates in response to the query. When the difference componentreceives a query and an associated secondary result set from a givensearch engine, the query and secondary result set are written to theproper per search engine data structure 204, 206 and 208. For example,assume that a given user executes a query for the search terms “Labradorretriever puppy adoption” at the search provider's search engine. Thedifference component, according to one or more previously describedtechniques, receives a secondary result set for the query from searchengine B 206. The difference component writes the search terms from thequery, as well as the secondary result set, to the per search enginedata structure for search engine B 206 in the result set data store 202.Accordingly, when the difference component must generate a differenceresult set, it may query the result set data store 202 for a given query210, 212, 216 to determine a secondary result set 224, 226, 228 from agiven search engine 204, 206 and 208, as opposed to retrieving thesecondary result set from the required search engine at runtime. Itshould also be noted that as users repeat execution of a given query210, 212 and 216, the secondary result set for the query 224, 226 and228 may be updated to reflect changes in the search algorithms used bysearch engines in generating the secondary result sets 224, 226 and 228.

One embodiment of a method for operating the system presented in FIG. 1for generating and presenting a difference result set on the basis of adifference between a primary result set and a secondary result set isillustrated in FIG. 3. According to the flow diagram of FIG. 3, a methodfor generating and presenting a difference result set comprisesgenerating a primary result set by a first search engine, step 302,which may generate the primary result set by applying a first searchalgorithm to a corpus of documents, e.g., HTML files, audio, video, textand combinations thereof. The method further comprises the generation ofa secondary result set by a second search engine, step 304, which maygenerate the secondary result set by applying a second search algorithmto a corpus of documents.

The primary and secondary result sets are used to determine a differenceresult set on the basis of one or more differences between the primaryresult set and the secondary result set, step 306. According to oneembodiment, the difference result set comprises a listing of a topnumber of results in the secondary result set, e.g., the top twentyitems in the secondary result set. The difference result set furthercomprises items from the primary result set that match items in thesecondary result set but differ in the rank assigned to the item. TableA presents an illustration of this exemplary difference result set:

TABLE A Search Engine A Search Engine B URL 1 5 www.urlA.com 2 7www.urlB.com 3 3 www.urlc.com 4 1 www.urld.com 5 4 www.urle.com 6 —www.urlf.com 7 — www.urlg.com

The difference result set may be stored in a persistent storage device,such as a hard disc drive, for presentation to the users requesting thedifference result set generated on the basis of differences between aprimary result set and a secondary result set, step 308. The system mayrecord a user's interaction with items in the difference result set,step 310, which may be used in weighting certain URLs when generatingthe primary result set. For example, where users consistently select theURL that is the number one search result from the difference result setthat is not the number one result in the primary result set, the searchengine may weight the URL such that it is assigned a higher rank in theprimary result set.

FIG. 4 presents an alternative embodiment of a method for generating andpresenting a difference result set on the basis of a difference betweena primary result set and a secondary result set. According to the methodof FIG. 4, one or more query terms comprising a query are received froma user on a client device, step 402. The system, e.g., through the useof a search engine at a search provider, generates a primary result seton the basis of the query terms that the user supplies, step 404. Thesystem performs a check to determine if a profile exists for the givenuser submitting the search query, step 406. Where a user profile exists,step 406, the system retrieves the user's attributes and preferencesfrom the user profile, step 408. The user profile may identify one ormore preferred search engines to use for generating a secondary resultset. Where no user profile exists, step 406, or where the user profiledoes not identify a preferred search engine, step 408, a defaultpreferred search engine is selected, which may be based on attributes ina user profile.

The system identifies a preferred search engine, either from a userprofile or by selecting a default preferred search engine, and performsa check to determine if a cached result set exists from the preferredsearch engine for the received query, step 410. Where a cached resultset from the preferred search engine for the received query exists, step410, the secondary result set is retrieved, step 412. Where a cachedresult set from the preferred search engine for the received query doesnot exist, step 410, a secondary search engine is queried with the queryterms received from the user, step 414. In response, the secondarysearch engine generates a secondary result set, step 416. A differenceresult set is generated on the basis of one or more differences betweenthe primary result set and the secondary result set, step 418. Forexample, assume that the user submits the query terms “Harry Potter”. Afirst search engine generates a primary result set. Where no cachedresult set exists from a preferred search engine, the preferred searchengine generates a secondary result set, which is used in conjunctionwith the primary result set to generate a secondary result set.

Continuing with FIG. 5, the system performs a check to determine if adifference button or control should be displayed in conjunction with theuser interface used to display the primary result set or other userinterface, step 502. The decision whether or not to present a differencebutton, step 502, may be made on the basis of a number of factors. Forexample, the difference button may be displayed where the user is aregistered user, on the basis of information in a user's profile, on thebasis of geography or location, etc. According to one embodiment, aregistered user is a user from which the system obtains information withwhich to recognize the user when he or she is accessing the system.

If the system determines that the difference button should not bepresented, step 502, the system simply presents the primary result set,step 504. A check is performed to determine if the user selects an itemfrom the primary result set, step 516. Where the user selects an itemfrom the primary result set, step 516, the user navigates to theselected item, which may include tracking an indication of the selectionin the user profile for the given user making the selection, step 518.Where no item is selected, step 516, processing returns to steps 502 and504, with continued presentation of the primary result set.

Where the system determines that it is to present the difference buttonto the user, step 502, the system presents the primary result set inconjunction with a difference button or other control, step 506. A checkis performed to determine if the user selects the difference button,step 508. Where the user has not selected the difference button, step508, the system performs a check to determine whether the user hasselected an item from the primary result set, step 516. Where the userhas selected neither the difference button, step 508, nor an item fromthe primary result set, step 516, the system awaits user input.

Where the user selects the difference button, step 508, the differenceresult set is presented to the user, step 510. The system may presentthe difference result set in a number of ways, including, but notlimited to, a dialog box, a separate browser window, within a dedicatedportion of the interface in which the system presents the primary resultset, etc. The system performs checks to determine if the user selects anitem from the difference result set, step 512, or from the primaryresult set, step 516. Where the user does not make any selection, thesystem awaits user input. If the user selects an item from thedifference result set, step 512, the system tracks the selection, whichmay include tracking the selection in a user profile for the given user,and navigates to the selected item, step 514. Similarly, if the userselects an item from the primary result set, step 516, the system tracksthe selection and navigates to the selected item, step 518. As discussedabove, tracking of the selection of items in the difference result setmay allow the system to use these data in influencing the searching forand ranking of documents, including, but not limited to text, audio,video, images and combinations thereof.

In addition to the foregoing, the system of the present invention mayalso determine and present a difference result set to a user on thebasis of searches that the user is conducting at a primary searchengine. FIG. 6 presents a flow diagram illustrating one embodiment of amethod for the presentation of a difference result set that the systemgenerates on the basis of multiple queries, which may be sequentialqueries. According to the embodiment of FIG. 6, a search engine receivesa primary query that comprises one or more query terms from a userinteracting with a client device, step 520. Alternatively, an automatedsystem or other software process may provide the query terms in theprimary query to the search application.

The system receives the primary query and generates a primary result seton the basis of the query terms, step 522, and presents items in theprimary result set to the user using the client device, step 524. Theuser submits a secondary search query and the system performs a check todetermine if the user is modifying the search terms in the primaryquery, step 528. For example, where the primary query comprises the term“golf” and the system receives a subsequent query from the user for“golf shoes”, the check at step 528 evaluates to true. It should benoted that the check that the system performs at step 528 is optional,and the system may execute the method illustrated at FIG. 6 where asecondary or any subsequent queries are not modifications of the primaryquery. According to the present embodiment, where the user is notmodifying the primary query, step 528, the process ends, step 526.

The system receives the query terms comprising the secondary query fromthe user interacting with the client device, step 530. The systemgenerates a secondary result set on the basis of the query terms, step532, and presents items in the secondary result set to the user usingthe client device, step 534. The interface that is presenting the itemsin the secondary result set to a user may also present a differencebutton, the selection of which causes the generation and presentation ofa difference result set. A number of factors may influence the decisionof whether to present the difference button, including, but not limitedto, a determination that a user is a registered user of the system, pastobserved behavior of the user, etc. A check is performed to determine ifthe user has selected the difference button, step 536.

Where the user selects the difference button, step 536, processingcontinues at step 540 with the system determining a difference resultset on the basis of the primary and secondary results sets, which areresponsive to the primary and secondary queries, respectively. Thesystem may determine a difference result set according to the techniquesdiscussed in connection with other embodiments or known to those ofskill in the art, e.g., according to URL matching techniques. Aninterface presents the difference result set to the user using theclient device, step 542, through which the user may interact with thedifference result set, such as by selecting items in the differenceresult set. Selection of the difference button may be recorded to createa profile of a user's past behavior, which may also include the user'sinteraction with the difference result set. According to one embodiment,the method excludes the presentation of the secondary result set andcheck for selection of the difference button, steps 534 and 536,respectively, and instead proceeds directly to the determination andpresentation of the difference result set, steps 540 and 542,respectively.

According to alternative embodiments of the invention, the system maydetermine one or more difference result sets for multiple sequentialqueries, e.g., performing a loop similar to that performed in thegeneration of a secondary result set (steps 536 through 528) for eachsequential query. By generating multiple result sets, which may includethe generation of multiple sequential result sets on the basis of aseries of modified queries, the method may determine multiple differencesets, as well as provide the user with controls for the same. Forexample, where the user executes a tertiary query, a secondarydifference result set may be determined on the basis of differencesbetween items in the difference result set and items in the tertiaryresult set, which is generated in response to the tertiary query. Theprocess of the present embodiment ends where the user does not selectthe difference button, step 538.

The system of the present invention may also provide an indication tothe user of the items in a primary result set that are also contained ina difference result set. The flow diagram of FIG. 7 illustrates oneembodiment of a method for determining and indicating items in adifference result set that are either exclusive to a primary result setor that are ranked above a threshold rank in a primary result but belowthe threshold in a secondary result set. For example, when a user isutilizing a primary search engine to generate a primary result set to aquery, the system of the present invention may be used according to themethod of FIG. 7 to indicate items in the primary result set that arenot contained in a secondary result set generated by a secondary searchengine. Additionally, the system of the present invention may be usedaccording to the method of FIG. 7 to indicate items ranked above athreshold value rank in a primary result set and not ranked above thesame threshold value in a secondary result set. The threshold may bepredefined or may read from a user profile.

According to the method of FIG. 7, a user submits a query, step 543, andthe system retrieves a primary result set, step 544. Retrieving theprimary result set may comprise generating the primary result set usinga first search engine, which may utilize a first search algorithm.Similarly, the system retrieves a secondary result set, step 546, whichmay comprise generating the secondary result set using a second searchengine. The secondary search engine may utilize a search algorithm thatis different from the first search algorithm. The choice of thesecondary search engine may be made in a number of ways, including, butnot limited to, an indication in a user profile, choosing from a set ofpotential secondary search engines, selecting a default secondary searchengine, etc. A difference result set is generated on the basis of one ormore differences between the primary result set and the secondary resultset, step 548.

An interface may present a user with a difference button or similarcontrol that allows the user to indicate items in the difference resultset, step 550. Alternatively, the user may set a preference in his orher user profile to determine whether the interface is to display thedifference button. Where the user is not shown the difference button,step 550, the system presents the user with the primary result set andrefrains from indicating the items in the difference result set, e.g.,items in primary result set that are not present in the secondary resultset, step 554.

Where the difference button is presented, step 550, the system performsa check to determine if the user selects the difference button, step552. Where the user selects the difference button, step 552, the systempresents the primary result set with an indication of the items in thedifference result set, step 556. The indication may comprise text,animation, video, images, such as an icon, etc. If the user does notselect the difference button, step 552, the system presents the userwith the primary result set and refrains from indicating the items inthe difference result set, step 554.

Those of skill in the art recognize that the method may enter a loop atstep 554 whereby the system continues to check to determine if the userselects the difference button, step 552, causing the presentation of anindication of items in the difference result set, step 556. Those ofskill in the art should further recognize that the method of FIG. 7 mayoperate such that the secondary result set is retrieved, steps 544 and546, respectively, and a difference result set calculated and used topresent exclusive items, steps 548 and 556, respectively, subsequent topresentation and selection of the difference button. The method of FIG.7 may also operate in a mode such that the items in the differenceresult set are indicated either by default or in response to the displayof the difference button whereby selection of the difference buttonallows the user to toggle the presentation of the one or moreindications on and off.

The system may present the difference button or similar control inconjunction with a primary result set, as illustrated at FIG. 8.According to the screen diagram presented by FIG. 8, a web browser 602,which may be executing on a client device, receives a web page 600 thatcomprises a primary result set that the system generates in response tothe user's query 612. The system ranks items 608 in the primary resultset according to one or more ranking algorithms. The user interface thatthe web page 600 provides comprises a difference button 610, theselection of which causes the presentation of a difference result set,which may include generation of the difference result set.

FIG. 9 illustrates the presentation of a difference result set 710 inconjunction with a primary result set 704. A web browser 702 executingon a client device receives a web page 700 comprising a primary resultset 704 and a difference button 708, in addition to other informationand user interface components. Selection of the difference button 708initiates presentation of a difference result set 710. According to theembodiment of FIG. 8, the difference result set 710 is rendered in adialog box presented in conjunction with the primary result set,although those of skill in the art recognize other techniques for thepresentation of information in a windowing environment may be utilized.The difference result set 710 comprises a listing of the top nineresults 712 from a search engine other than the search engine utilizedto generate the primary result set 704, e.g., the secondary result set.The difference result set also provides the corresponding rank that thegiven item in the secondary result set occupies in the primary resultset 714, as well as the URL for the item 716. Selection of a URL 716 bythe user results in the system tracking the selection of the URL 716 andthe browser 702 navigating to the selected URL 716.

FIG. 10 presents a screen diagram illustrating an indication of items ina result set that are exclusive to a primary search engine that isgenerating the result set, e.g., a result set from a secondary searchengine does not contain the item in the result set from the primarysearch engine or an item ranked above a threshold value in a primaryresult set appears below the threshold value in a secondary result set.A web browser 802 executing on a client device receives a web page 800comprising a primary result set that the system generates in response tothe user's query 804, in addition to other information and userinterface components. The system ranks items 806 in the primary resultset according to one or more ranking algorithms. The user interface thatthe web page 800 provides also comprises an indication 808 of any itemsin the primary result set 806 that are not contained in a secondaryresult set. A difference button 810 allows the user to toggle thedisplay of the indication 808 of the exclusive items.

While the invention has been described and illustrated in connectionwith preferred embodiments, many variations and modifications as will beevident to those of skill in the art may be made without departing fromthe spirit and scope of the invention, and the invention is thus not tobe limited to the precise details of methodology or construction setforth above as such variations and modification are intended to beincluded within the scope of the invention.

1. A method for determining a result set on the basis of sequentialsearches to determine difference between the sequential searches, themethod comprising: receiving a primary result set comprising one or moreitems in response to a first search query, the first search querycomprising a first set of one or more search terms; receiving asecondary result set comprising one or more items in response to asecond search query, the second search query comprising a second set ofone or more search terms, wherein receiving the primary result set andthe secondary result set includes receiving two sequential searches;determining a difference between the two sequential searches with theone or more items in the primary result set and the one or more items inthe secondary result set to determine a difference result set, thedifference result set: (1) containing the one or more items in thesecondary result set that is not included in the primary result set; (2)containing the one or more items in the primary result set that isincluded in the secondary result set; and (3) excluding one or moreitems in the primary result set not included in the secondary resultset; displaying the one or more items in the difference result set to auser, the difference result set revolves around the secondary resultset; displaying a difference button to the user, the selection of whichinitiates display of the difference result set; and determining whetherthe user is a registered user; and when the user is a registered user,displaying the difference button.
 2. The method of claim 1 comprising:receiving a tertiary result set comprising one or more items in responseto a third search query, the third search query comprising a third setof one or more terms that are a derivative of the second set of one ormore search terms; determining the difference between the one or moreitems in the tertiary result set and the one or more items in thedifference result set to determine a secondary difference result set,the secondary result set comprising one or more items; and displayingthe one or more items in the secondary difference result set to theuser.
 3. The method of claim 2 wherein receiving a primary result set, asecondary result and tertiary result set comprises receiving threesequential searches.
 4. The method of claim 1 comprising generating thefirst result set and the second result set according to a first searchalgorithm.
 5. The method of claim 1 comprising generating the firstresult set according to a first search algorithm and generating thesecond result set according to a second search algorithm.
 6. The methodof claim 1 comprising: retrieving a past-observed behavior of the user;and displaying the difference button on the basis of the past-observedbehavior.
 7. The method of claim 6 wherein retrieving the past-observedbehavior comprises retrieving from a profile for the user.